1. Field of Invention
This invention relates generally to multimedia devices. More specifically, the invention describes a method and apparatus that automatically normalizes the volume of a recording based upon both the selectivity and the sensitivity of the human auditory system.
2. Description of Related Art
Recent developments in consumer electronics have included the introduction of portable multimedia asset player devices such as MP3 players, minidisk players, and the like. For example, in the case of an MP3 player, a number of digitized audio files in the form of MP3 files are stored in a storage medium included in or coupled to the player in a fashion deemed most suitable to that user. In the case of MP3 files, a user can select and digitally encode any number of music selections each of which could have been mastered (i.e., the original recording from which all other recordings are derived) at different volume levels. Unfortunately, when these various MP3 files are played back on an appropriate MP3 player, for example, the various volume levels for each other encoded MP3 files will result in each recording having its own perceived volume forcing the user to manually re-adjust the volume, or gain, of each song thereby disrupting what would otherwise be an effortless and enjoyable listening experience by forcing the user to manually re-adjust the perceived volume, or loudness, of each song.
Therefore, what is required is a method and apparatus for automatically normalizing the volume of any number of digitally encoded multimedia asset files, (such as MP3 files) in, for example, an MP3 player.